Display apparatus, control method thereof and control method of external device

ABSTRACT

A display apparatus, a control method thereof and a control method of an external device are provided. The display apparatus includes a contents processing unit which reproduces contents, a communication unit which communicates with an external device which reproduces contents, and a control unit which receives reproduction information of the contents reproduced in the external device from the external device through the communication unit, and controls the contents processing unit to reproduce contents corresponding to the contents reproduced in the external device, based on the received reproduction information.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This application claims priority from Korean Patent Application No.10-2008-0029649, filed on Mar. 31, 2008 in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein in itsentirety by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Methods and apparatuses consistent with the present invention relate toa display apparatus which communicates with an external device and amethod thereof, and more particularly to a display apparatus whichreproduces contents of the external device and a method thereof.

2. Description of the Related Art

A display apparatus is used as a television (TV), a monitor, and etc.The display apparatus reproduces contents provided by cable or wirelesstransmission, to be displayed as an image. The display apparatus used asa TV receives an image signal through a cable or antenna, extractscontents from the image signal, and displays the contents. A PortableMedia Player (PMP) which is able to reproduce contents is provided andthis mobile device downloads digitally filed contents from contentsproviders or computer stations.

Conventionally, for a user to view the contents stored in a mobiledevice using a TV, the mobile device is connected with the TV and sendsthe contents of the mobile device to the TV which reproduces thecontents.

There is a case that a user who watches the contents wants to stopreproducing the contents and watch the contents continuously from thesame position in the display apparatus. If the display apparatus doesnot know the last reproduced position, a user must search for is thelast reproduced position in the mobile device by himself. For example,the user must search how much time passed since reproduction started.

Conventionally, there is no special restriction to access the displayapparatus by the mobile device. It is possible to reproduce contents ofunspecified mobile device in the display apparatus. It is possible forunauthenticated contents to be reproduced unintentionally in the displayapparatus.

SUMMARY OF THE INVENTION

An aspect of the present invention is to provide a display apparatuswhich reproduces contents reproduced in an external device continuouslyfrom last reproduced position in the external device and a controlmethod thereof.

Another aspect of the present invention is to provide a displayapparatus which receives data from an external device selectivelythrough authentication and a control method thereof.

According to an aspect of the invention, there is provided a displayapparatus comprising a contents processing unit which reproducescontents, a communication unit which communicates with an externaldevice which reproduces contents, and a control unit which receivesreproduction information of contents reproduced in the external devicethrough the communication unit and controls the contents processing unitto reproduce contents corresponding to the contents reproduced in theexternal device, based on the received reproduction information.

The control unit may control the contents processing unit to reproducethe contents continuously from a last position reproduced in theexternal device.

The control unit may receive from the external device the contentsreproduced in the external device and reproduces the contents reproducedin the external device.

The display apparatus may further comprise a storage unit which storescontents, wherein the control unit controls the contents processing unitto reproduce the contents stored in the storage unit based on thereceived reproduction information if the storage unit stores samecontents as the contents stored in the external device.

The control unit may receive the reproduction information which includesfirst position information for reproducing the contents reproduced inthe external device.

The reproduction information received in the control unit may furthercomprise at least one of codec information for the contents stored inthe external device and order information for reproducing a plurality ofthe contents stored in the external device.

The display apparatus may further comprise an on-screen display (OSD)generating unit which displays a message of asking whether to reproducethe contents from reproduction position corresponding to the firstposition information for reproduction, wherein the control unitreproduces the contents from the reproduction position if reproductionof the contents is selected after the message is displayed.

The control unit may generate second position information forreproducing the contents processed in the contents processing unit andsend the second position information to the external device for thecontents to be reproduced from position which corresponds to secondposition information in the external device.

The communication unit may communicate with the external device bywireless transmission and the control unit may receive the reproductioninformation selectively from the external device which enters in acommunication possible area of the communication unit.

The display apparatus may further comprise a user input unit whichselects whether to reproduce the contents corresponding to the contentsin the external device, wherein the control unit controls the contentsto be reproduced when the external device enters in the communicationpossible area if the user input unit selects to reproduce the contentsin advance and the control unit does not control the contents to bereproduced when the external device enters in the communication possiblearea if the user input unit selects not to reproduce the contents inadvance.

The display apparatus may further comprise an authentication unit whichauthenticates the external device which enters in the communicationpossible area, wherein the control unit receives the reproductioninformation from the external device which is authenticated by theauthentication unit and does not receive the reproduction informationfrom the external device which is not authenticated by theauthentication unit.

The authentication unit may receive an authentication key stored in theexternal device and determines whether to authenticate the externaldevice based on the received key.

The control unit may control the OSD generating unit to generate amessage for requesting authentication of the external device if theexternal device which enters in the communication possible area is notauthenticated.

The control unit may generate an authentication key for the externaldevice if the request is accepted and sends the key to the externaldevice.

According to an aspect of the invention, there is provided a controlmethod of a display apparatus comprising receiving reproductioninformation of contents reproduced in an external device from theexternal device which reproduces the contents, and reproducing contentscorresponding to the contents reproduced in the external device, basedon the received reproduction information.

The reproducing contents may comprise reproducing the contentscontinuously from a last position reproduced in the external device.

The reproducing contents may comprise receiving the contents reproducedin the external device. The reproducing contents may comprisereproducing the contents stored in the display apparatus based on thereceived reproduction information if the display apparatus stores samecontents as the contents stored in the external device.

The receiving reproduction information may comprise receiving thereproduction information which includes first position information forreproducing the contents reproduced in the external device.

The reproduction information further may comprise at least one of codecinformation for the contents stored in the external device and orderinformation for reproducing a plurality of the contents stored in theexternal device.

The reproducing contents may comprise displaying a message of askingwhether to reproduce the contents from reproduction positioncorresponding to the first position information for reproduction, andreproducing the contents from the reproduction position if reproductionof the contents is selected.

The reproducing contents may comprise generating second positioninformation for reproducing the contents reproduced in the displayapparatus, and sending the second position information to the externaldevice for the contents to be reproduced from position which correspondsto second position information in the external device.

The receiving reproduction information may comprise receiving thereproduction information selectively from the external device whichenters in a wireless communication possible area.

The control method may further comprise selecting whether to reproducethe contents corresponding to the contents in the external device beforethe receiving reproduction information, wherein the receivingreproduction information comprises reproducing the contents when theexternal device enters in the communication possible area if reproducingthe contents is selected in the selecting whether to reproduce thecontents and not reproducing the contents when the external deviceenters in the communication possible area if not reproducing thecontents is selected in the selecting whether to reproduce the contents.

The receiving the reproduction information selectively from the externaldevice may comprise determining whether the external device isauthenticated, and receiving the reproduction information from theexternal device if the external device is authenticated and notreceiving the reproduction information from the external device if theexternal device is not authenticated.

The determining whether the external device is authenticated comprisesdetermining whether to authenticate the external device based on anauthentication key received from the external device.

The determining whether the external device is authenticated maycomprise displaying a message for requesting authentication of theexternal device if the external device is not authenticated.

The determining whether the external device is authenticated may furthercomprise generating an authentication key for the external device if therequest is accepted, and sending the key to the external device.

A control method of an external device which communicates with a displayapparatus may comprise reproducing contents, generating reproductioninformation of the contents, and sending the reproduction information tothe display apparatus for reproducing contents corresponding to thecontents reproduced in the external device, based on the reproductioninformation.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects and features of the present invention willbe apparent from the following detailed description of exemplaryembodiments taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 illustrates a display apparatus and an external device accordingto an exemplary embodiment of the present invention;

FIG. 2 is a block diagram of a display apparatus and a mobile deviceaccording to an exemplary embodiment of the present invention;

FIG. 3 is a flow chart of contents reproduction operations in a displayapparatus based on contents reproduction information in a mobile device;

FIG. 4 illustrates an exemplary message whether to reproduce contents ofa mobile device in a display apparatus;

FIG. 5 is a flow chart of operations for sending position informationfor reproducing contents which is reproduced in a display apparatus to amobile device;

FIG. 6 is a flow chart of operations for reproducing contents in amobile device based on position information for reproducing contentsreceived from a display apparatus; and

FIG. 7 is a flow chart of authenticating a mobile device in a displayapparatus.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION

Hereinafter, exemplary embodiments of the present invention will bedescribed in detail with reference to the accompanying drawings. Theaspects and features of the present invention and methods for achievingthe aspects and features will be apparent by referring to the exemplaryembodiments to be described in detail with reference to the accompanyingdrawings. However, the present invention is not limited to the exemplaryembodiments disclosed hereinafter, but can be implemented in diverseforms. The matters defined in the description, such as the detailedconstruction and elements, are merely specific details provided toassist those of ordinary skill in the art in a comprehensiveunderstanding of the invention, and the present invention is onlydefined within the scope of the appended claims.

FIG. 1 illustrates a display apparatus 1 and an external device 10according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the display apparatus 1 receives and reproducescontents from an external image source (not shown). In the exemplaryembodiment, the contents include an image and sound, but it is possiblefor the contents to include only one of an image and sound. The displayapparatus 1 may receive the contents from various kinds of imagesources, for example, a broadcasting station may provide the contents bya cable or wireless transmission. The display apparatus 1 maycommunicate with the external device 10 which stores the contents. Theexternal device 10 according to an exemplary embodiment of the presentinvention may be implemented as a mobile device which a user can carry,but the external device 10 is not limited to the mobile device.

The mobile device 10 is a device which stores and reproduces digitallyfiled contents and by which a user can enjoy the contents anytime andanywhere. The mobile device 10 may be implemented as a Portable MediaPlayer (PMP), an MP3 player, a portable computer, and etc.

The display apparatus 1 may communicate with the mobile device 10,receive the contents which are stored in the mobile device 10, andreproduce the contents. The display apparatus 1 receives contentsreproduction information and reproduces the contents based on thecontents reproduction information.

Various kinds of methods may be applied to the communication between thedisplay apparatus 1 and the mobile device 10. The display apparatus 1according to the exemplary embodiment may wirelessly communicate withthe mobile device 10. The communication between the display apparatus 1and the mobile device 10 is possible if the mobile device 10 enters acommunication area C of the display apparatus 1. The communicationmethod is not limited to wireless communication. It is possible for thecommunication between the display apparatus 1 and the mobile device 10to be implemented by cable transmission.

The display apparatus 1 may be implemented to communicate only with anauthenticated mobile device such as the mobile device 10. In detail, ifthe display apparatus 1 recognizes that the mobile device 10 enters tothe communication area C, the display apparatus 1 attempts toauthenticate the mobile device 10. If the display apparatus 1successfully authenticates the mobile device 10, the display apparatus 1receives the contents and the content reproduction information from themobile device 10. If the display apparatus 1 cannot authenticate themobile device 10, the display apparatus 1 does not receive the contentsand the contents reproduction information from the mobile device 10.

Structures of the display apparatus 1 and the mobile device 10 will beexplained in detail with reference to FIG. 2. FIG. 2 is a block diagramof the display apparatus 1 and the mobile device 10 according to anexemplary embodiment of the present invention.

The display apparatus 1 comprises a communication unit 100 whichcommunicates with the mobile device 10, contents processing unit 200which processes the contents received from the mobile device 10 to bereproduced, and a control unit 900 which controls reproduction of thecontents based on the content reproduction information received from themobile device 10.

The display apparatus 1 further comprises a display unit 300 and aspeaker 400 which reproduce the processed contents in the contentsprocessing unit 200, an On Screen Display (OSD) generating unit 500which processes a message to be displayed on the display unit 300, auser input unit 600 through which a user inputs commands, anauthentication unit 700 which authenticates the mobile device 10, and astorage unit 800 which stores data such as the contents.

The mobile device 10 comprises a mobile device (MD) communication unit11 which communicates with the communication unit 100, an MD storageunit 13 which stores the contents, an MD display unit 15 whichreproduces the contents, and a control unit 17 which controls the otherunits.

The communication unit 100 communicates with the mobile device 10 whichis in the communication area C and receives the contents and the contentreproduction information from the mobile device 10. A wirelesscommunication method such as a Wireless Universal Serial Bus (WUSB) andBluetooth may be used in the communication unit 100. By utilizing thesekinds of wireless communication methods, the mobile device 10 maycommunicate by entering in the communication area C without beingphysically connected to the display apparatus 1.

The contents processing unit 200 processes an image of the contents tobe displayed on the display unit 300 and a sound of the contents to beoutput through the speaker 400. The contents processing unit 200 mayperform decoding according to a format of the contents, processing forimproving image quality, scaling for adjusting a size of the image,display style adjustment according to a request of a user, etc.

The contents processing unit 200 comprises various kinds of codec ordecoders and chooses a decoder corresponding to the format of thecontents and performs decoding under control of the control unit 900. Ifthere are multiple decoders corresponding to the contents, the contentsprocessing unit 200 may choose a proper decoder. For example, thecontents processing unit 200 may choose a decoder which provides mostimproved image quality.

The display unit 300 displays an image of the contents which isprocessed by the contents processing unit 200. The display unit 300 maybe implemented a plasma display panel (PDP), liquid crystal display(LCD), etc. The speaker 400 outputs the sound processed by the contentsprocessing unit 200.

The OSD generating unit 500 generates messages about user's selections.The messages may be related to selection whether the display apparatus 1reproduces the contents of the mobile device 10 and whether the displayapparatus 1 starts to reproduce the contents from the last reproducedposition in the mobile device 10. One of the messages may be related toa request of registration to a user if the mobile device 10 is notregistered in the display apparatus 1.

The OSD generating unit 500 generates the messages and outputs themessages to be displayed on the display unit 300. After a user views themessages, the user can select operations of the display apparatus 1 inresponse to the messages. The OSD generating unit 500 may display apassword input window with the messages to prevent an unauthorized userfrom accessing the display unit 300. In this case, the control unit 900may perform the user's command only if the password input by a usermatches a registered password.

The user input unit 600 is provided for a user to manipulate, and sendsthe manipulation information input by the user to the control unit 900for a user to be able to control the display apparatus 1. The user inputunit 600 may comprise menu keys provided on the exterior of the displayapparatus 1, a remote controller, etc. If a user views the OSD message(P in FIG. 4) and selects one of the choices, the user input unit 600sends the user's selection information to the control unit 900.

If the mobile device 10 in the communication area C is registered in thedisplay apparatus 1, the authentication unit 700 performs authenticationfor the mobile device 10. The authentication unit 700 receives anauthentication key from the mobile device 10 and determines based on theauthentication key whether the mobile device 1 is allowed tocommunicate.

The authentication unit 700 may be implemented by a micro chip or by asoftware program. If the authentication unit 700 is implemented by asoftware program, the control unit 900 may execute the software program.

The storage unit 800 stores the contents to be processed by the contentsprocessing unit 200. If the contents are received from the mobile device10, the contents are stored in the storage unit 800 to be processed bythe contents processing unit 200. The storage unit 800 may beimplemented by a hard disc drive, a flash memory, etc.

The control unit 900 receives from the mobile device 10 the contents andthe contents reproduction information at that time the mobile device 10reproduced the contents, through the communication unit 100. The controlunit 900 controls the contents processing unit 200 to reproduce thecontents received from the mobile device 10.

The contents reproduction information received by the control unit 900may comprise various kinds of information. For example, the contentsreproduction information may comprise position information forreproducing the contents, file route information of the contents storedin the mobile device 10, order information for reproducing a pluralityof contents, codec information for reproducing the contents, etc. Thecontrol unit 900 may recognize the stored location of the contents usingthe file route information, control the plurality of contents to bereproduced according to the order information, and determine whether itis possible to reproduce the contents in the contents processing unit200 based on the codec information.

The control unit 900 receives the position information for reproducingthe contents and controls the contents processing unit 200 to reproducethe contents continuously from the last position the contents werereproduced in the mobile device 10.

If a user chooses “YES” as an answer to the message (P) which asks “doyou want to reproduce contents of the mobile device continuously fromthe last reproduced position?”, the control unit 900 controls for thecontents to be reproduced from the last reproduced position in themobile device 10.

The control unit 900 may generate position information for reproducingthe contents which are processed in the contents processing unit 200 andsends the position information for reproducing the contents to themobile device 10. In this exemplary embodiment, the contents processedin the contents processing unit 200 are the contents received from themobile device 10. It is possible for the mobile device 10 to reproducethe contents continuously from the last reproduced position in thedisplay apparatus 1 after the contents are reproduced in the displayapparatus 1.

In the case of sending and receiving the contents and the contentsreproduction information, the control unit 900 may allow the sending andreceiving only to a specified mobile device 10. That is, the controlunit 900 may allow the mobile device 10 which is authenticated by theauthentication unit 700 to send and receive data, but prevent a mobiledevice which fails to be authenticated from sending and receiving data.

The control unit 900 controls the OSD generating unit 500 to display amessage for requesting authentication to the mobile device 10 if themobile device 10 is not authenticated. If the request is accepted, thecontrol unit 900 generates an authentication key for the mobile device10 and sends the key to the mobile device 10. The authentication unit700 authenticates the mobile device 10 based on the authentication key.If the request is not accepted, the control unit 900 prevents the mobiledevice 10 from sending and receiving data.

The MD communication unit 11 uses a communication method compatible withthe communication unit 100 for the mobile device 10 to communicate withthe display apparatus 1.

The MD storage unit 13 stores at least one contents and reproductioninformation for the contents. It may be desirable for the MD storageunit 13 to be implemented by a nonvolatile memory such as a flash memoryfor not losing stored data.

The MD display unit 15 displays an image of the contents stored in theMD storage unit 13 and may be implemented by a PDP or an LCD panel. Aspeaker may be provided for outputting sound.

The MD control unit 17 controls for the contents to be reproduced in themobile device 10 and stores contents reproduction information,especially the position information of the contents reproduced in themobile device 10. If the display apparatus 1 requests the contents andthe contents reproduction information, the MD control unit 17 sends therequested contents and contents reproduction information via the MDcommunication unit 11.

Reproduction of the contents from the last reproduced position in themobile device 10 will be explained with reference to FIGS. 2 and 3.

FIG. 3 is a flow chart of contents reproduction operations in thedisplay apparatus 1 based on the contents reproduction information inthe mobile device 10.

The control unit 900 recognizes that the mobile device 10 enters in thecommunication area (C) (S100). The authentication unit 700 attempts toauthenticate the mobile device 10. If the authentication unit 700successes to authenticate, data transmission between the communicationunit 100 and the MD communication unit 11 becomes possible (S110).

The control unit 900 receives the contents and the contents reproductioninformation from the mobile device 10 (S120). The control unit 900determines whether the received contents can be processed in thecontents processing unit 200, that is, whether the received contents canbe reproduced in the display apparatus 1 (S130).

Various methods for determining whether the received contents can bereproduced in the display apparatus 1 can be utilized. For example, thedisplay apparatus 1 determines whether the contents processing unit 200can decode the received contents using the codec information of thecontents which is included in the contents reproduction information orthe display apparatus 1 may determine whether the contents can bereproduced by decoding a part of the contents in advance.

If it is determined the contents are decodable, the message that asks“do you want to reproduce contents of the mobile device continuouslyfrom the last reproduced position?” is displayed on the display unit 300by the OSD generating unit 500 (S140) as shown in FIG. 4. If a userchooses “Yes” using the user input unit 600, the control unit 900 causesthe contents to be reproduced from the last reproduced position in themobile device 10 (S150).

If the contents are not decodable in the display apparatus 1 or a userchooses “No” in response to the message of operation S140, the controlunit 900 controls the display unit 300 to display an error message(S160). By these operations, the contents which were reproduced in themobile device 10 may be reproduced in the display apparatus 1 and may bereproduced from the last reproduced position in the mobile device 10.

It is also possible for the contents to be reproduced continuously inthe mobile device 10 from the last reproduced position in the displayapparatus 1. An exemplary embodiment of this case is explained referringto FIGS. 2, 5, and 6.

FIG. 5 is a flow chart of operations for sending the positioninformation for reproducing the contents which is reproduced in thedisplay apparatus 1 to the mobile device 10.

Referring to FIG. 5, the control unit 900 controls the contentsprocessing unit 200 to reproduce the contents (S200). The contents maybe received from the mobile device 10 or may be received from sourcesother than the mobile device 10.

A user chooses whether to send the position information for reproducingthe contents to the mobile device 10 through the user input unit 600(S210).

If a user chooses to send the position information, the control unit 900generates position information for reproducing the contents (S220) andsends the position information to the mobile device 10 through thecommunication unit 100 (S230). After sending the position informationfor reproducing the contents is finished, the control unit 900 may storeor delete the position information for reproducing the contents in thestorage unit 800.

FIG. 6 is a flow chart of operations for reproducing the contents in themobile device 10 based on the position information for reproducing thecontents received from the display apparatus 1.

If the position information for reproducing the contents is receivedfrom the display apparatus 1, the MD control unit 17 stores the positioninformation for reproducing the contents in the MD storage unit 13(S300). The MD control unit 17 checks whether the mobile device 10 hasthe contents corresponding to the received position information forreproducing (S310), when the MD control unit 17 tries to reproduce thecorresponding contents in the mobile device 10.

If there are the corresponding contents, the MD control unit 17 causesthe contents to be reproduced continuously from the last reproducedposition which is received (S320). If there are no correspondingcontents, the MD control unit 17 causes an error message to be displayed(S330).

By this process, it becomes possible to reproduce the contentscontinuously from the last reproduced position in the display apparatus1, in the mobile device 10.

If the contents sent to the mobile device 10 are the contents which weresent to the display apparatus 1 from the mobile device 10, the mobiledevice 10 already has the contents. In this case, the positioninformation for reproducing the contents is sent from the displayapparatus 1 to the mobile device 10, but the contents do not need to besent.

Processes for authenticating the mobile device 10 which enters in thecommunication possible area (C) and allowing to receive and send dataand processes for registering the mobile device 10 which is notregistered in the display apparatus 1 are explained referring to FIGS. 2and 7.

FIG. 7 is a flow chart of authenticating the mobile device 10 in thedisplay apparatus 1.

Referring to FIG. 7, if the mobile device 10 enters in the communicationpossible area (C) S400, the control unit 900 recognizes the mobiledevice 10 (S410). The control unit 900 determines whether the recognizedmobile device 10 is a new device which is not registered in the displayapparatus 1 (S420).

There are various methods for the control unit 900 to determine whetherthe recognized mobile device 10 is a new device. For example, a methodfor reading device information of the mobile device 10 and checkingwhether there is corresponding information stored in the storage unit800 of the display apparatus 1 or a method for determining based onwhether an authentication key is stored in the mobile device 10 arepossible.

If the recognized mobile device 10 is not a new device, that is, if therecognized mobile device 10 is registered already, the control unit 900receives an authentication key stored in the mobile device 10 (S430).The authentication key is generated and given to the mobile device 10 atthe time when the mobile device 10 is registered first.

The authentication unit 700 performs authentication based on thereceived authentication key (S440). The control unit 900 determineswhether the authentication by the authentication unit 700 is successful(S450).

If the authentication is successful, the control unit 900 allows datacommunication between the display apparatus 1 and the mobile device 10(S460) so that the contents and the contents reproduction information inthe mobile device 10 may be sent to the display apparatus 1.

If the authentication is not successful, the control unit 900 preventsdata communication between the display apparatus 1 and the mobile device10 (S490).

If the mobile device 10 is determined as a new device which is notregistered in the display apparatus 1, the control unit 900 controls theOSD generating unit 500 to display a message for asking to register thenew mobile device 10 on the display unit 300 (S470).

If a user does not agree to register the new mobile device 10, thecontrol unit 900 prevents data communication between the displayapparatus 1 and the mobile device 10 (S490). In particular, if a useragrees to register the new mobile device 10, the control unit 900generates an authentication key for the mobile device 10 and sends thekey to the mobile device 10 (S480). The sent authentication key isstored in the mobile device 10. The authentication key is sent to thedisplay apparatus 1 again when the authentication unit 700 performsauthentication.

After the authentication key is sent, the control unit 900 recognizesthe mobile device 10 again and performs authentication.

By the authentication of the mobile device 10 by the display apparatus1, an unspecified mobile device 10 may be prevented from receiving andsending data to the display apparatus 1.

The above exemplary embodiments are directed to a case that displayapparatus 1 receives the contents and the contents reproductioninformation together, but the present invention is not limited to thiscase. For example, the contents corresponding to the contents stored inthe MD storage unit 13, that is, substantially same contents, may bestored in the storage unit 800. In this case, the contents are stored inboth of the display apparatus 1 and the mobile device 10. In this case,if the display apparatus 1 reproduces the contents, it is possible toreceive from the mobile device 10 only the position information forreproducing the contents without the contents. Alternatively, it ispossible to receive the contents from an external device which isconnected to the display apparatus 1 and the reproduction informationcorresponding to the contents from the mobile device 10.

There are various kinds of methods for registering and authenticating anew mobile device 10. For example, in operation S480 of FIG. 7 in whichthe control unit 900 generates an authentication key and sends the keyto the mobile device 10, the control unit 900 may generate a couple ofauthentication keys which correspond to each other. The displayapparatus 1 and the mobile device 10 may store respective authenticationkeys. In the authentication operations S430 and S440 of theauthentication unit 700, the control unit 900 may match theauthentication key of the recognized mobile device 10 and theauthentication key of the display apparatus 1. If the keys are matched,the authentication is considered successful. However, the presentinvention is not limited to this example of an authentication process.

A user may select whether the display apparatus 1 reproduces thecontents continuously from the last position reproduced in the mobiledevice 10. If a user selects for the display apparatus 1 to reproducethe contents continuously from the last position reproduced in themobile device 10, it is possible for the contents of the mobile device10 to be reproduced in the display apparatus 1 continuously from thelast position reproduced in the mobile device 10.

Referring to FIGS. 1 and 2, a user may select whether the displayapparatus 1 reproduces the contents continuously from the last positionreproduced in the mobile device 10 or display apparatus 1 do notreproduce the contents in advance. The user's selection may be stored inthe storage unit 800 for the control unit 900 to refer.

If the mobile device 10 enters in the communication possible area (C),the control unit 900 may search the user's selection stored in thestorage unit 800 already.

If the user's selection is to reproduce the contents from the lastposition reproduced in the mobile device 10, the control unit 900performs authentication of the mobile device 10 and reproduction of thecontents like the above exemplary embodiments.

If the user's selection is not to reproduce the contents, the controlunit 900 does not perform authentication of the mobile device 10 orreproduction of the contents even if the control unit 900 recognizes themobile device 10. Even if the mobile device 10 enters in thecommunication possible area (C) during a contents is reproduced in thedisplay apparatus 1, the display apparatus 1 does not display themessage (P) of FIG. 4. It may prevent the message of FIG. 4 fromdisplaying and the contents of the mobile device 10 from beingreproduced unintentionally during a user watches contents of the displayapparatus 1.

Although exemplary embodiments of the present invention have beendescribed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope and spirit of the inventionas disclosed in the accompanying claims.

1. A display apparatus comprising: a communication unit which receivescontents and reproduction information from a mobile device external tothe display apparatus, wherein the reproduction information identifiescontents which were previously displayed on the mobile device; acontents processing unit which reproduces the contents from the mobiledevice and displays the contents on a display unit of the displayapparatus; and a control unit which receives the reproductioninformation from the communication unit and controls the contentsprocessing unit to reproduce the contents which were previouslydisplayed on the mobile device on the display apparatus, wherein thecontrol unit controls the contents processing unit based on thereproduction information to reproduce the contents continuously from alast position that the contents were displayed on the mobile device,wherein the reproduction information comprises first positioninformation for reproducing the contents reproduced in the mobiledevice, and wherein the control unit generates second positioninformation for reproducing the contents processed in the contentsprocessing unit and sends the second position information to the mobiledevice for the contents to be reproduced on the mobile device from aposition which corresponds to the second position information.
 2. Thedisplay apparatus of claim 1, wherein the control unit receives from themobile device the contents previously displayed on the mobile device andreproduces the contents previously displayed on the mobile device on thedisplay unit of the display apparatus.
 3. The display apparatus of claim1, further comprising a storage unit which stores contents, wherein thecontrol unit controls the contents processing unit to reproduce thecontents stored in the storage unit based on the received reproductioninformation if the contents stored in the storage unit are the same asthe contents stored in the mobile device.
 4. The display apparatus ofclaim 1, wherein the reproduction information further comprises codecinformation for the contents stored in the mobile device and orderinformation for reproducing a plurality of the contents stored in themobile device.
 5. The display apparatus of claim 1, further comprisingan on screen display (OSD) generating unit which displays a message ofrequesting whether to reproduce the contents from a reproductionposition corresponding to the first position information, wherein thecontrol unit controls the contents processing unit to reproduce thecontents from the reproduction position if reproduction of the contentsis selected in response to the message which is displayed.
 6. Thedisplay apparatus of claim 1, wherein the communication unitcommunicates with the mobile device by wireless transmission and thecontrol unit receives the reproduction information selectively from themobile device which enters in a communication area of the communicationunit.
 7. A display apparatus comprising: a communication unit whichreceives contents and reproduction information from a mobile deviceexternal to the display apparatus, wherein the reproduction informationidentifies contents which were previously displayed on the mobiledevice; a contents processing unit which reproduces the contents fromthe mobile device and displays the contents on a display unit of thedisplay apparatus; and a control unit which receives the reproductioninformation from the communication unit and controls the contentsprocessing unit to reproduce the contents which were previouslydisplayed on the mobile device on the display apparatus, wherein thecontrol unit controls the contents processing unit based on thereproduction information to reproduce the contents continuously from alast position that the contents were displayed on the mobile device,wherein the communication unit communicates with the mobile device bywireless transmission and the control unit receives the reproductioninformation selectively from the mobile device which enters in acommunication area of the communication unit, wherein the displayapparatus further comprises: a user input unit through which a userselects whether to reproduce the contents on the display apparatus whichwere previously displayed on the mobile device, and wherein the controlunit controls the contents processing unit to reproduce the contentswhen the mobile device enters in the communication area if it isselected to reproduce the contents via the user input unit in advance,and the control unit does not control the contents processing unit toreproduce the contents when the mobile device enters in thecommunication area if it is selected not to reproduce the contents viathe user input unit in advance.
 8. The display apparatus of claim 6,further comprising an authentication unit which authenticates the mobiledevice which enters in the communication area, wherein the control unitreceives the reproduction information from the mobile device which isauthenticated by the authentication unit and does not receive thereproduction information from the mobile device which is notauthenticated by the authentication unit.
 9. The display apparatus ofclaim 8, wherein the authentication unit receives an authentication keystored in the mobile device and determines whether to authenticate themobile device based on the received authentication key.
 10. The displayapparatus of claim 8, wherein the control unit controls the OSDgenerating unit to generate a message for requesting authentication ofthe mobile device if the mobile device which enters in the communicationarea is not authenticated.
 11. The display apparatus of claim 10,wherein the control unit generates an authentication key for the mobiledevice if the request is accepted and sends the key to the mobiledevice.
 12. A control method of a display apparatus comprising:receiving reproduction information from a mobile device external to thedisplay apparatus, wherein the reproduction information identifiescontents which were previously displayed on the mobile device; andreproducing the contents on the display apparatus which were previouslydisplayed on the mobile device, based on the received reproductioninformation, wherein the reproduction information comprises firstposition information for reproducing the contents reproduced in themobile device, and wherein the reproducing contents comprises:generating second position information for reproducing the contentsreproduced in the display apparatus; and sending the second positioninformation to the mobile device for the contents to be reproduced onthe mobile device from a position which corresponds to the secondposition information.
 13. The control method of claim 12, wherein thereproducing contents on the display apparatus comprises reproducing thecontents continuously from a last position that the contents weredisplayed on the mobile device.
 14. The control method of claim 13,wherein the reproducing contents comprises receiving the contents at thedisplay apparatus that were previously displayed on the mobile device.15. The control method of claim 13, wherein the reproducing contentscomprises reproducing the contents stored in the display apparatus basedon the received reproduction information if the contents stored in thedisplay apparatus stores are the same as the contents stored in themobile device.
 16. The control method of claim 12, wherein thereproduction information further comprises at least one of codecinformation for the contents stored in the mobile device and orderinformation for reproducing a plurality of the contents stored in themobile device.
 17. The control method of claim 12, wherein thereproducing contents comprises: displaying a message of requestingwhether to reproduce the contents from a reproduction positioncorresponding to the first position information; and reproducing thecontents from the reproduction position if reproduction of the contentsis selected in response to the message which is displayed.
 18. Thecontrol method of claim 12, wherein the receiving reproductioninformation comprises receiving the reproduction information selectivelyfrom the mobile device which enters in a wireless communication area ofthe display.
 19. A control method of a display apparatus comprising:receiving reproduction information from a mobile device external to thedisplay apparatus, wherein the reproduction information identifiescontents which were previously displayed on the mobile device; andreproducing the contents on the display apparatus which were previouslydisplayed on the mobile device, based on the received reproductioninformation, wherein the receiving reproduction information comprisesreceiving the reproduction information selectively from the mobiledevice which enters in a wireless communication area of the display, andwherein the control method further comprises selecting whether toreproduce the contents on the display apparatus which were previouslydisplayed on the mobile device before the receiving the reproductioninformation, and wherein the receiving reproduction informationcomprises reproducing the contents when the mobile device enters in thecommunication area if reproducing the contents is selected in theselecting whether to reproduce the contents; and not reproducing thecontents when the mobile device enters in the communication area if notreproducing the contents is selected in the selecting whether toreproduce the contents.
 20. The control method of claim 18, wherein thereceiving the reproduction information selectively from the mobiledevice comprises: determining whether the mobile device isauthenticated; and receiving the reproduction information from themobile device if the mobile device is authenticated; and not receivingthe reproduction information from the mobile device if the mobile deviceis not authenticated.
 21. The control method of claim 20, wherein thedetermining whether the mobile device is authenticated comprisesdetermining whether to authenticate the mobile device based on anauthentication key received from the mobile device.
 22. The controlmethod of claim 20, wherein the determining whether the mobile device isauthenticated comprises displaying a message for requestingauthentication of the mobile device if the mobile device is notauthenticated.
 23. The control method of claim 22, wherein thedetermining whether the mobile device is authenticated furthercomprises: generating an authentication key for the mobile device if therequest is accepted; and sending the authentication key to the mobiledevice.
 24. A control method of a mobile device which communicates witha display apparatus comprising: displaying contents on the mobiledevice; generating reproduction information of the contents displayed onthe mobile device which identifies the contents which were displayed onthe mobile device; and sending the contents and the reproductioninformation from the mobile device to the display apparatus forreproducing the contents which were displayed on the mobile device onthe display apparatus, wherein the control method further comprisesprocessing by the display apparatus the contents received from themobile device, the processing comprises adjusting the contents displayedby the mobile device to the display by the display apparatus, whereinthe processing comprises selecting a decoder from a plurality of thedecoders, which decodes a format corresponding to the format of thecontents displayed by the mobile device, and wherein the decoder isfurther selected based on whether the decoder provides an improved imagequality.
 25. The display apparatus of claim 1, wherein the communicationunit receives together the contents and the reproduction information.26. The display apparatus of claim 1, wherein the content processingunit reproduces the contents stored in the mobile device based on thereproduction information.
 27. The display apparatus of claim 26, whereinthe reproduction information comprises at least one of file routeinformation for locating on the mobile device files comprising thecontents, order information for reproducing the contents, and codecinformation for reproducing the contents.
 28. The method of claim 12,wherein the contents are stored in both the mobile device and thedisplay apparatus.
 29. The method of claim 24, further comprising thedisplay apparatus searching user predefined settings stored in themobile device, wherein if the mobile device is within a vicinity of thedisplay apparatus, determining whether to switch displaying the contentsfrom the mobile device to the display apparatus based on the userpredefined settings, and automatically switching the displaying of thecontents if the user predefined settings request said switch.
 30. Themethod of claim 24, wherein the mobile device is within the vicinity ofthe display apparatus if the mobile device is connected via cable to thedisplay apparatus or if the mobile device enters a communication area inwhich the mobile device is able to communicate with the displayapparatus wirelessly.
 31. The method of claim 24, wherein the processingcomprises at least one of improving image quality of the contents,scaling for adjusting a size of the contents, and display styleadjustment.